I don't get the vitriol either. There's a lot that can be learned from this guy, and he does keep a stable of writers in suds and spuds. (I seem to remember they get a flat fee of $250,000 per book, but I could be wrong about that.)
Some other folks up-thread said they'd hook their wagons to his star just for that. Who wouldn't want to make that much cash in a year? And if they're especially adroit, they could probably squeeze out two books a year.
At any rate... Patterson's obviously shattered a lot of paradigms. Even The King hasn't gone the same route and managed the same financial success, but I suspect the difference lies in that SK is a former academic, whereas JP is a veteran of the ad biz. For sure, SK's history served him well in producing the base product itself (and even then and now, he has his critics), but JP's background serves him in a much different way, and in a fashion that might elude most scribes: he knows how to package a product.
Two approaches, both wind up generating millions. One tried and true, the other true only once the personality involved was able to get it tried.